# multiband orthogonal frequency division mutlplexing (UWB) (MB-OFDM)

Multiband-OFDM ( MB-OFDM) is a technology for high-speed short-range radio presented by the WiMedia Alliance. According to WiMedia's ideas, MB-OFDM is intended to connect peripheral devices to the personal computer by radio at high speed. All peripheral devices, whether scanners, camcorders, graphics tablets, touch screens, monitors, printers or plotters, can thus communicate directly and wirelessly with the personal computer at a data rate of 480 Mbps.

Orthogonal Frequency Division Multiplex (OFDM) divides the available frequency band into several subcarriers. In MB-OFDM, there are 128 subcarriers distributed in a 528 MHz wide channel. Each subcarrier is modulated to reach its maximum when the adjacent subcarriers have their lowest modulation amplitude. Each subcarrier is modulated with a portion of the data stream. In MB-OFDM, three 528 MHz channels are combined into a frequency band group in each case. That is, a frequency band group covers a frequency band of 1.584 GHz. The frequency range released for ultra-wideband between 3.1 GHz and 10.6 GHz is divided into five 1.5 GHz frequency bands. A maximum data rate of 480 Mbit/s can be achieved in each 528 MHz channel. The spectral efficiency is 0.9 bit/s/ Hz.

The transmission itself takes place on three frequency bands, with the channel being changed after each OFDM symbol. Quadrature phase shift ke ying( QPSK) is used to achieve data rates between 53 Mbit/s and 480 Mbit/s over distances of 11 m (53 Mbit/s) and 3 m (10 ft). Higher data rates can be achieved with quadrature amplitude modulation (16QAM).

An alternative technique to MB-OFDM is Direct Sequence UWB( DS-UWB).